Objective To investigate the factors in relation with the case fatality in severe meconium aspiration syndrome (MAS). Methods Eighty-one severe MAS cases intervened by the mechanical ventilation from 9 childrens hospitals were retrospectively analyzed for the risk factors of fatality with SAS software for non-parametric rank sum test and chi-square test. Results In the 81 cases, 49 were survived (death rate 39%). The gestational age (GA), Apgars score at 1min and other complications with MAS were significantly related to the death (P 0.05). Conclusion A higher death rate (close to 40%) of severe MAS in the middle of 1990s in major cities of China suggests that it is important to detect the intrauterine hypoxemia as it may indicated by meconium staining amniotic fluid which should be intervened early by adequate termination of pregnancy before 42 weeks. The effects of delivery room suction and conventional ventilation also need to be reevaluated.